good place to start would be with the federal law, specifically 18 U.S.C. 1503. The criminal code demands more than what Comey reportedly describes in his memo. There are dozens of different variations of obstruction charges ranging from threatening witnesses to influencing jurors. None would fit this case. That leaves the omnibus provision on attempts to interfere with the “due administration of justice.”

However, that still leaves the need to show that the effort was to influence “corruptly” when Trump could say that he did little but express concern for a longtime associate. The term “corruptly” is actually defined differently under the various obstruction provisions, but it often involves a showing that someone acted “with the intent to secure an unlawful benefit for oneself or another.” Encouraging leniency or advocating for an associate is improper but not necessarily seeking an unlawful benefit for him.

Then there is the question of corruptly influencing what? There is no indication of a grand jury proceeding at the time of the Valentine’s Day meeting between Trump and Comey. Obstruction cases generally are built around judicial proceedings — not Oval Office meetings.

Of course, that does not change the fact that the question by Trump was wildly inappropriate. Yet, it also raises questions of Comey’s judgment. The account suggests that Comey was so concerned about the conversation that he wrote a memorandum for record. But that would suggest that Comey thought the president was trying to influence the investigation but then said nothing to the Justice Department or to his investigation team. The report says that, while Comey may have told a couple of colleagues at the FBI, he did not tell the investigation team “so the details of the conversation would not affect the investigation.”

Why? If he thought the president was trying to derail the investigation, that would seem relevant to the scope of the investigation. It is like a bank president seeking to close a fraud investigation, but the contact in the FBI decided not to tell bank investigators. One explanation would be that Comey did not view Trump as a potential target of the Flynn investigation, and thus did not view the uncomfortable meeting as relevant to the investigation team (and Trump has maintained that Comey told him three times that he was not a target). However, that would make the case even weaker for allegations that Trump was trying to protect himself or his inner circle by seeking closure for Flynn.

It is highly concerning that Trump has described how Comey actively campaigned to keep his job during this period. As usual, Trump has created the most problematic record for judging his own actions. If Comey was pleading for his job as suggested by Trump, the impropriety of the alleged statement in the Oval Office would be exponentially increased. Trump categorically denies that the statement was ever made. That alone could support an immediate demand for any and all tapes in the possession of Trump and he would be required to turn them over.

There is a separate question of whether this type of alleged obstruction could be the basis for impeachment. As someone who has been down that long impeachment road before, I would again advocate caution. Last night, respected former presidential advisor David Gergen said that, with the Comey memo, we are now “in impeachable territory.” If so, we have one foot on the shore and one in a raging surf. Before we start an impeachment proceeding, we need to be on terra firma. It requires more than uncomfortable meetings or ill-considered disclosures.

It is certainly true that an impeachable offense does not have to be a prosecutable crime despite the standard of “treason, bribery or high crimes and misdemeanors.” Professors like Laurence Tribe and others have called for impeachment, even before this latest allegation. It is also true that Richard Nixon was facing impeachment allegations that included efforts to influence or obstruct the investigation of his campaign.

However, Nixon’s impeachment involved a host of clear criminal acts from slush funds to burglaries. There is still no compelling evidence of an actual crime at the heart of the Russian investigation. Flynn is facing allegations of basic reporting or disclosure violations under the Foreign Agents Registration Act (FARA) which is rarely actually prosecuted. Indeed, there have been only seven prosecutions under FARA since 1966, when the law was revised.

The investigation of Flynn has not produced any reported evidence implicating Trump. A FARA violation is a relatively minor federal violation for a president if that is the scope of the FBI investigation. Obviously, if there is some undisclosed major crime implicating the president, the seriousness of the alleged statement would grow in the same proportion. However, Trump has insisted that he was told repeatedly by Comey that he was not under investigation.

Impeachment is not meant to be an alternative for criminal cases that cannot be submitted to a grand jury. It is also not meant to be politics by other means. Finally, it is not a vehicle to redo an election for those with morning-after regrets. Ironically, for those who charge that Trump has compromised the legal system, the same objection can be made over demands for criminal charges or impeachment based on his still undisclosed memo.

Fortunately, there is ample reason to expect answers to these questions. There is a paper trial and witnesses. Moreover, by discussing aspects of these conversations with Comey, Trump has undermined claims of privilege and has made it easier for Comey to speak to Congress. However, absent tapes, this could well end up as a “he said, he said” dispute.

For all of these reasons, we need to move beyond the hyperventilated pronouncements of criminal conduct or impeachable offenses based on this memo. This conversation in the Oval Office is a valid matter of concern and worthy of further investigation. It is not proof of an impeachable offense any more than it is proof of a crime.

Jonathan Turley is the Shapiro Professor of Public Interest Law at George Washington University. He testified during the Clinton impeachment and serves as the lead defense counsel in the last impeachment trial in the U.S. Senate for Judge Thomas Porteous.